Conventionally, a content can be provided from a server on a network to a renderer under control of a controller. Concretely, in nonpatent reference 1, a system in which a controller, which is called a control point, controls both a server and a renderer on a network so as to transfer a content in the server to the renderer transferred thereto, and the renderer decodes the content and displays this decoded content is described. In the above-mentioned system, when the format of the content stored in the server differs from any format which the renderer supports, the transcoder in the server converts the format of the content and then provides this content to the renderer.
Patent reference 1 further discloses, as a related technology, an information processing apparatus provided with an adding means for adding information which is used for performing a process on streaming data to the streaming data, a storing means for storing the streaming data to which the information is added, and a transmitting means for transmitting the streaming data including the information which are stored in the storing means, and further including a transcoder which transcodes them to streaming data as information.
Patent reference 2 discloses a transcoder which is provided with a request processing means for receiving a streaming request made by a client from a network to convert the streaming request, and for transmitting the converted streaming request to a server in behalf of the client, a reply processing means for receiving a reply to the streaming request from the server, and for converting the reply to transmit the converted reply to the client, and a transcoder processing means for converting stream data transmitted from the server, and for transmitting the converted stream data to the client according to both client information and content information in the server which are acquired through the transmission of the streaming request and the reply to the streaming request, and which converts the amount of codes of the stream data, and so on properly in such a way as to support for a required band at the time of communications between the client and the server.    [Patent reference 1] JP.2002-342192.A (see paragraphs 0008 and 0011)    [Patent reference 2] JP.2002-374298.A (see paragraph 0193)    [Nonpatent reference 1] UPnP AV Architecture V.83 Jun. 12, 2002, pp. 1 to 22 (Universal Plug and Play Forum—www.upnp.org)
A problem with the above-mentioned conventional methods is that because a transcoder is included in either each server or each renderer according to the methods, in order to increase the number of content formats which can be supported, many transcoders must be prepared in either each server or each renderer.
Although it can be considered that contents which are coded in many formats are prepared in each server in order to make it possible for the system to support for various formats and methods, such a preparation is not realistic because the required number of formats and the required number of methods are huge.
The present invention is made in order to solve the above-mentioned problems, and it is therefore an object of the present invention to provide a transcoder which does not need to prepare many transcoders in either each server or each renderer in order to increase the number of content formats which can be supported, and which can convert a content having various formats which is stored by each server into a content having a format which each renderer can play back, and can provide the content to each renderer.